From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file

---
 kernel/net/packet/af_packet.c |   74 ++++++++++++++++++++++---------------
 1 files changed, 44 insertions(+), 30 deletions(-)

diff --git a/kernel/net/packet/af_packet.c b/kernel/net/packet/af_packet.c
index eaa030e..bbdb32a 100644
--- a/kernel/net/packet/af_packet.c
+++ b/kernel/net/packet/af_packet.c
@@ -269,7 +269,8 @@
 
 static bool packet_use_direct_xmit(const struct packet_sock *po)
 {
-	return po->xmit == packet_direct_xmit;
+	/* Paired with WRITE_ONCE() in packet_setsockopt() */
+	return READ_ONCE(po->xmit) == packet_direct_xmit;
 }
 
 static u16 packet_pick_tx_queue(struct sk_buff *skb)
@@ -365,18 +366,20 @@
 {
 	union tpacket_uhdr h;
 
+	/* WRITE_ONCE() are paired with READ_ONCE() in __packet_get_status */
+
 	h.raw = frame;
 	switch (po->tp_version) {
 	case TPACKET_V1:
-		h.h1->tp_status = status;
+		WRITE_ONCE(h.h1->tp_status, status);
 		flush_dcache_page(pgv_to_page(&h.h1->tp_status));
 		break;
 	case TPACKET_V2:
-		h.h2->tp_status = status;
+		WRITE_ONCE(h.h2->tp_status, status);
 		flush_dcache_page(pgv_to_page(&h.h2->tp_status));
 		break;
 	case TPACKET_V3:
-		h.h3->tp_status = status;
+		WRITE_ONCE(h.h3->tp_status, status);
 		flush_dcache_page(pgv_to_page(&h.h3->tp_status));
 		break;
 	default:
@@ -393,17 +396,19 @@
 
 	smp_rmb();
 
+	/* READ_ONCE() are paired with WRITE_ONCE() in __packet_set_status */
+
 	h.raw = frame;
 	switch (po->tp_version) {
 	case TPACKET_V1:
 		flush_dcache_page(pgv_to_page(&h.h1->tp_status));
-		return h.h1->tp_status;
+		return READ_ONCE(h.h1->tp_status);
 	case TPACKET_V2:
 		flush_dcache_page(pgv_to_page(&h.h2->tp_status));
-		return h.h2->tp_status;
+		return READ_ONCE(h.h2->tp_status);
 	case TPACKET_V3:
 		flush_dcache_page(pgv_to_page(&h.h3->tp_status));
-		return h.h3->tp_status;
+		return READ_ONCE(h.h3->tp_status);
 	default:
 		WARN(1, "TPACKET version not supported.\n");
 		BUG();
@@ -1885,11 +1890,19 @@
 
 static void packet_parse_headers(struct sk_buff *skb, struct socket *sock)
 {
+	int depth;
+
 	if ((!skb->protocol || skb->protocol == htons(ETH_P_ALL)) &&
 	    sock->type == SOCK_RAW) {
 		skb_reset_mac_header(skb);
 		skb->protocol = dev_parse_header_protocol(skb);
 	}
+
+	/* Move network header to the right position for VLAN tagged packets */
+	if (likely(skb->dev->type == ARPHRD_ETHER) &&
+	    eth_type_vlan(skb->protocol) &&
+	    vlan_get_protocol_and_depth(skb, skb->protocol, &depth) != 0)
+		skb_set_network_header(skb, depth);
 
 	skb_probe_transport_header(skb);
 }
@@ -1985,7 +1998,7 @@
 		goto retry;
 	}
 
-	if (!dev_validate_header(dev, skb->data, len)) {
+	if (!dev_validate_header(dev, skb->data, len) || !skb->len) {
 		err = -EINVAL;
 		goto out_unlock;
 	}
@@ -2135,7 +2148,7 @@
 	sll = &PACKET_SKB_CB(skb)->sa.ll;
 	sll->sll_hatype = dev->type;
 	sll->sll_pkttype = skb->pkt_type;
-	if (unlikely(po->origdev))
+	if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV)))
 		sll->sll_ifindex = orig_dev->ifindex;
 	else
 		sll->sll_ifindex = dev->ifindex;
@@ -2408,7 +2421,7 @@
 	sll->sll_hatype = dev->type;
 	sll->sll_protocol = skb->protocol;
 	sll->sll_pkttype = skb->pkt_type;
-	if (unlikely(po->origdev))
+	if (unlikely(packet_sock_flag(po, PACKET_SOCK_ORIGDEV)))
 		sll->sll_ifindex = orig_dev->ifindex;
 	else
 		sll->sll_ifindex = dev->ifindex;
@@ -2815,7 +2828,8 @@
 		packet_inc_pending(&po->tx_ring);
 
 		status = TP_STATUS_SEND_REQUEST;
-		err = po->xmit(skb);
+		/* Paired with WRITE_ONCE() in packet_setsockopt() */
+		err = READ_ONCE(po->xmit)(skb);
 		if (unlikely(err != 0)) {
 			if (err > 0)
 				err = net_xmit_errno(err);
@@ -3005,6 +3019,11 @@
 	skb->mark = sockc.mark;
 	skb->tstamp = sockc.transmit_time;
 
+	if (unlikely(extra_len == 4))
+		skb->no_fcs = 1;
+
+	packet_parse_headers(skb, sock);
+
 	if (has_vnet_hdr) {
 		err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le());
 		if (err)
@@ -3013,12 +3032,8 @@
 		virtio_net_hdr_set_proto(skb, &vnet_hdr);
 	}
 
-	packet_parse_headers(skb, sock);
-
-	if (unlikely(extra_len == 4))
-		skb->no_fcs = 1;
-
-	err = po->xmit(skb);
+	/* Paired with WRITE_ONCE() in packet_setsockopt() */
+	err = READ_ONCE(po->xmit)(skb);
 	if (unlikely(err != 0)) {
 		if (err > 0)
 			err = net_xmit_errno(err);
@@ -3146,6 +3161,9 @@
 
 	lock_sock(sk);
 	spin_lock(&po->bind_lock);
+	if (!proto)
+		proto = po->num;
+
 	rcu_read_lock();
 
 	if (po->fanout) {
@@ -3248,7 +3266,7 @@
 	memcpy(name, uaddr->sa_data, sizeof(uaddr->sa_data));
 	name[sizeof(uaddr->sa_data)] = 0;
 
-	return packet_do_bind(sk, name, 0, pkt_sk(sk)->num);
+	return packet_do_bind(sk, name, 0, 0);
 }
 
 static int packet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
@@ -3265,8 +3283,7 @@
 	if (sll->sll_family != AF_PACKET)
 		return -EINVAL;
 
-	return packet_do_bind(sk, NULL, sll->sll_ifindex,
-			      sll->sll_protocol ? : pkt_sk(sk)->num);
+	return packet_do_bind(sk, NULL, sll->sll_ifindex, sll->sll_protocol);
 }
 
 static struct proto packet_proto = {
@@ -3472,7 +3489,7 @@
 		memcpy(msg->msg_name, &PACKET_SKB_CB(skb)->sa, copy_len);
 	}
 
-	if (pkt_sk(sk)->auxdata) {
+	if (packet_sock_flag(pkt_sk(sk), PACKET_SOCK_AUXDATA)) {
 		struct tpacket_auxdata aux;
 
 		aux.tp_status = TP_STATUS_USER;
@@ -3856,9 +3873,7 @@
 		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 
-		lock_sock(sk);
-		po->auxdata = !!val;
-		release_sock(sk);
+		packet_sock_flag_set(po, PACKET_SOCK_AUXDATA, val);
 		return 0;
 	}
 	case PACKET_ORIGDEV:
@@ -3870,9 +3885,7 @@
 		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 
-		lock_sock(sk);
-		po->origdev = !!val;
-		release_sock(sk);
+		packet_sock_flag_set(po, PACKET_SOCK_ORIGDEV, val);
 		return 0;
 	}
 	case PACKET_VNET_HDR:
@@ -3969,7 +3982,8 @@
 		if (copy_from_sockptr(&val, optval, sizeof(val)))
 			return -EFAULT;
 
-		po->xmit = val ? packet_direct_xmit : dev_queue_xmit;
+		/* Paired with all lockless reads of po->xmit */
+		WRITE_ONCE(po->xmit, val ? packet_direct_xmit : dev_queue_xmit);
 		return 0;
 	}
 	default:
@@ -4020,10 +4034,10 @@
 
 		break;
 	case PACKET_AUXDATA:
-		val = po->auxdata;
+		val = packet_sock_flag(po, PACKET_SOCK_AUXDATA);
 		break;
 	case PACKET_ORIGDEV:
-		val = po->origdev;
+		val = packet_sock_flag(po, PACKET_SOCK_ORIGDEV);
 		break;
 	case PACKET_VNET_HDR:
 		val = po->has_vnet_hdr;

--
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